Help me with my first *and* ridiculous build

Hey folks,

I currently ride a geared Condor and want two things from my second ride: firstly to try out this whole "fixed gear" craze that I hear the kids go crazy for these days...

The second is disc brakes. The dual pivots on my Condor are so appalling in the far from infrequent rain that it really annoys me. I don't think any future bike I make should have to have rim brakes again.

So, I've done a fair amount of research and my favourite option so far, by far, is the Cotic Roadrat frame. My main worry is that a Large is 54cm seat tube, and even though it has semi-MTB geometry, I'm going to be at the limit of a 350mm seatpost on that. I'm 6'4", btw.

It's a lot like the Surly Karate Monkey frame (a 29er with horizontal dropouts) (which gets eliminated mostly due to the horrible name) - i.e. it has horizontal dropouts (132.5 spaced for road or MTB hubs (but not track...)), disc and canti mounts and comes in a 'short' style for use with drops.

Also, because I do quite like gears, I may want the option to go to a 1x9 setup later, hence I'm thinking of buying a normal 130mm casette hub and using the Surly Fixxer kit to convert it to fixed.

So, I'm thinking something like:

• Roadrat Frame & Fork (Large/Short)
  
• Avid BB7R disc brake on the front
  
• Bullhorn bars with an end mounted TT brake lever for the disc (I much prefer this look/style to the finger brake on the tops)
  
• Alex R450 wheelset with IS disc mounts (Cotic supply these on OTP RoadRat builds, so it's the easiest option, though I could be persuaded otherwise)
  
• Surly Fixxer (need more research to make sure it plays nice with the Alex 450s)
  
• Headset/seatpost/stem: unknown, probably the cheaper end of the scale to avoid this being hilariously expensive. Still have to decide on silver vs. black too...
  
• Chainset: unknown. A track set won't work so need to convert a double with spacers (and take off a ring) or use something like the Shimano Alfine... though I think it's ugly and am not sure if I should worry about 170 vs 165mm cranks on a build like this? I am looking forward to having the robustness of a Hollowtech II type BB though :)
  
  
  

Obviously, instead of all this I could buy a cheap OTP like a Charge Plug or an even cheaper beater fixed... but I kinda want to learn the build side of things too, and I'm fairly handy with a spanner... usually :)

So...
1.) am I insane? This'll probably cost like £800+
2.) Is there anything above that definitely won't work?
3.) any other options / insights / things to consider?

In terms of looks, I'm thinking black frame/fork, silver headset/stem/bars/seatclamp and maybe seatpost, brown/leather type saddle/bar tape. So it'll be a weird bullhorned disc braked, pseudo MTB geo'd fixed gear with classic understated looks... !

Flame on!